X-ray control means



J u ne 14, 1938. c. B. HORSLEY ET AL X-RAY CONTROL MEANS Filed March 11,1937 FIG. 2

{EN VENT 0R5 CAPERTON HORSLEY BY EDWIN R. GOLDFIELD Patented June 14,1938 UNITED STATES PATENT OFFICE Goldfield, University Heights, Ohio,assignors to Picker X-Ray Corporation Waite Manufacturing Division,Inc., Cleveland, Ohio, a corporation' of Ohio Application March 11,

2 Claims.

This invention relates to means for controlling the high tension circuitof an X-ray tube and the controlling means contemplated by the inventionprovides both compensation for variations in line voltage, and means forselectively operating the tube at any of the several kilovoltages whichthe technique of the apparatus demands.

Objects of the invention are to provide an extremely compact arrangementfor the purpose, adapted for use in a portable control unit for the tubeserved, and more particularly to provide but a single handle by whichthe operator may make both sets of adjustments, in an exceedingly simplemanner.

The exact nature of this invention together with further objects andadvantages thereof will be apparent from the following description takenin connection with the accompanying drawing, in which Fig. 1 is adiagrammatic view showing a typical X-ray tube control circuit embodyingthe invention; Fig. 2 is a face view of the high tension circuitcontroller appearing in Fig. 1; and Fig. 3 illustrates in typicallongitudinal section, a physical embodiment of the controller switchmeans appearing in Fig. 1.

With reference now to the drawing, X is the X-ray tube which is to beserved by the alternating current line L1, L2, the tube having for itsfilament control, a filament transformer PI and filament control FC, andfor its high tension circuit a high tension transformer HT, inversevoltage suppressor S, and exposure switch E. An input transformer IT isarranged to be effective between the line L1, L2, and the partsdescribed, and a voltmeter V and milliammeter MA are arranged in thecircuit to serve the usual purposes.

What has thus far been described will be appreciated by one familiarwith the art as generally typical of the latter, and it will be apparentthat the high tension circuit of the tube is controllable by control ofthe primary circuit of its high tension transformer HT.

The input transformer IT is conveniently an auto-transformer and anumber of leads or taps are provided for its windings, all as indicatedin Fig. 1 of the drawing, wherein the leads are indicated as a seriesfrom O to 135.

The line L1, L2, being nominally at 110 volts but actually its voltagevarying at times down to say 105 and up to say 125 volts, we providemeans effective between the line and the input transformer IT to adjustthe transformer to the line. As here shown such means comprises a switchA connected on one side to the line L2 as by the connection a and havinga number of points 1937, Serial No. 130,296

marked 0 to 9, the switch being shown as upon the point (I which is adead point. The points I, 4 and I are all connected to the I25 lead tothe transformer IT, the points 2, 5 and 8 are connected to the H5transformer lead and the points 3, 6 and 9 to the I05 lead.

Supposing the leads of the transformer IT to indicate relative turnunits in the transformer winding, and the L1 side of the line beingconnected to the transformer IT at the lead 50, it will be apparent thatwhen the switch A is on point I, 4 or I, the line will be effectiveacross that portion of the transformer IT between its leads I25 and 50,which is '75 turn units. Similarly, when the switch A is on point 2, 5or 8, the line will be effective between the leads H5 and 50, or turnunits, and when the switch is on point 3, 6 or 9, the line will beeffective between the leads I05 and 50, or 55 turn units.

As indicated in Fig. 1, one side of the primary winding of the hightension tube transformer HT is connected to one end of the inputtransformer IT as by the line b in which are located the voltagesuppressor S and exposed switch E. The opposite end of the high tensiontransformer primary winding is connected to a switch B which controlsits relation to the transformer IT. The switch B is preferably,according to our invention, physically connected with the switch A tomove with the latter, but electrically insulated therefrom, as indicatedin Figs. 1 and 3. As to the physical relation of the parts, the switchesare preferably arranged for coaxial movement as indicated in Figs. 1 and3 so that a single handle AB may be provided for coincident control ofboth switches. In Fig. 3 the parts are shown as with the switch A on itspoint 2, the point I lying there opposite, and the switch B aligned withthe switch A.

The switch B is provided with three segmental points including a pointI23 so located that the switch B will be on this point when the switch Ais on any of its points I, 2 or 3, a second point 456 so located that itwill be on this point when the switch A is on any of the points 4, 5 or6, and l a third point I89 so located that it will be on this point whenthe switch A is on any of its points I, 8 or 9. The point I23 isconnected to the lead of the transformer IT, the point 456 to the I02lead and the point I89 to the I35 or high end lead of the transformer.

It will be apparent then that when the switch B is on its point I23, thehigh tension transformer HT will be served by 80 turn units of thetransformer IT, when the switch B is on its point 456, 102 turn units ofthe transformer IT will be available, and when the switch B is on itspoint 189, the entire transformer IT with its 135 turn units will beavailable. Obviously, therefore, the three points of the switch 13selectively provide for the high tension circuit of the tube, threedifferent operating conditions for the tube, such that the tube mayoperate at any of three kilovolt ratings selected by the operator in theusual manner according, for example, to the sections encountered inradiographic practice.

The face of the apparatus may be calibrated as indicated in Fig. 2,showing 10 points for the switch AB which, as here illustrated, is onits 0 point or off position. Corresponding to the points of the switchB, the face shows three ranges designated as Low, Medium and High. Foreach of these three ranges the corresponding three points of the Aswitch are indicated as IE5, H5 and I25, in approximation of the actualvoltages met in the nominal 110 volt line L1, L2. The operator then,with the aid of the voltmeter V and knowing the desired kilovolts to beapplied to the X-ray tube X, can easily select the proper position forthe switch AB which will thus by a single setting of a single handle,give him a close approximation to ideal control of the high tensioncircuit of the tube under the instant circumstances. It is understoodthat ordinarily in operation of the apparatus as a whole, the handle ABis properly set before closure of the switch E to actually energize thetube.

What we claim is:

1. Means for controlling the high tension circuit of an X-ray tube fromits supply line and comprising a transformer, primary switch meansarranged to vary the relation of said line to said transformer,secondary switch means arranged to vary the relation of said transformerto said tube, an operator-operated control member, each of said switchmeans including a part connected to said control member for movementresponsive thereto, and said switch means including contactors soarranged that for each relation established by one switch means a seriesof relations may be selected for the other switch means.

2. Means for controlling the high tension circuit of an X-ray tube fromits supply line and comprising a transformer, primary switch meansarranged to vary the relation of said line to said transformer,secondary switch means arranged to vary the relation of said transformerto said tube, said switch means including coaxially movable partsinterconnected for their coincident operation as a unit, and said switchmeans including contactors so arranged that for each relationestablished by one switch means, a series of relations may be selectedfor the other switch means.

CAPERTON B. I-IORSLEY. EDWIN R. GOLDFIELD.

